The present invention comprises a new and distinct cultivar of calla lily, botanically known as Zantedeschia sprengeri and hereinafter referred to by the cultivar name ‘Gold Label’.
‘Gold Label’ is a product of a planned breeding program, which had the objective of creating Zantedeschia hybrids for pot flower production in a wide range of colors with a large, classic flower shape. The breeding program began in 1989, and the new cultivar is a seedling selected from the crossing of a Zantedeschia sprengeri variety named ‘Goldilocks’ (female parent, unpatented) with a Zantedeschia sprengeri variety named ‘Summer Sun’ (male parent, U.S. Plant Pat. No. 27,892). ‘Gold Label’ was selected in 2012 by the inventor in 't Zand, The Netherlands as one flowering plant within the progeny of the stated cross.
The first act of asexual reproduction of ‘Gold Label’ by tissue culture was performed by the inventor in September of 2012 in 't Zand, The Netherlands. Subsequent asexual reproductions by tissue culture at the same location have demonstrated that the combination of characteristics as herein disclosed for the new cultivar are retained and reproduced true to type through successive generations of asexual reproduction.
The following observations, measurements and comparisons describe plants grown from 12 to 14 weeks in 14 cm pots in 't Zand, The Netherlands under greenhouse conditions, which approximate those generally used in horticultural practice. Color references are made to The 2001 R.H.S. Colour Chart of The Royal Horticultural Society of London, except where general color terms of ordinary significance are used.
The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variations in environment without a change in the genotype of the plant.
The following traits have been repeatedly observed and determined to be basic characteristics of ‘Gold Label’ which, in combination, distinguish this calla lily as a new and distinct cultivar:                1. Dark yellow-colored spathes; and        2. High inflorescence production.        
Further, when compared to calla lily plant named ‘Sunclub’ (U.S. Plant Pat. No. 27,891), the upper surface spathe color of ‘Sunclub’ varies between Yellow Group RHS 12A and 12B, whereas the upper surface spathe color of ‘Gold Label’ varies between Yellow Group RHS 7A to 9A.
Table 1 provides similarities and differences of ‘Gold Label’ to its parents, Zantedeschia sprengeri variety ‘Goldilocks’ and Zantedeschia sprengeri variety ‘Summer Sun’.
TABLE 1‘Gold Label’SimilaritiesDifferences‘Goldilocks’Spathe shapeSpathe colorLeaf maculationsLess inflorescences than‘Goldilocks’Taller than ‘Goldilocks’‘Summer Sun’Plant heightSpathe colorNumber of inflorescences‘Gold Label’ has a largerspathe size